For me, I look at the overall workflow. I've personally never been disappointed by the output from Lightroom, with regard to the raw conversion. This is just my personal opinion, but there's no way I'm going to stop using a fast workflow that Lightroom gives me, just to get some perceived improvement in the sharpness or whatever....and I can guarantee that anyone that looks at my photos would never ever wonder "Gee, I bet he used Lightroom for that...it could be a little more sharp" I'm not trying to be controversial, but I just think this issue is blown way out of proportion. No one looking at a photo at normal viewing distances (for prints) and not blown up to 100% or more on the screen would ever notice any difference. It's slightly possible that an expert X-Trans raw conversion pixel peeper might notice it....but I can say even I would have no clue what software someone used just by looking at a photo normally.

So, I personally wouldn't use another converter just to convert and then re-import that TIFF or JPG to another application for further editing.

For me it's all about the workflow as a whole....and Lightroom really does do quite well with the X100S files, like this one I think so anyway...